Photoshop Tutorial: Scenery in a Bottle (or any other enclosed space)!

Here is a fun little tutorial that is open to a lot of creativity. I'll show you how to put a picture into a bottle or lightbulb or anything you can really think of.
Here are the steps:
Step 1: Save the bulb and tree image I have provided in this card. If you have another idea, then go and find your own pictures! Make sure to get a high resolution image, you'll thank me later.
Step 2: Open both images into photoshop.
Step 3: I used the lightbulb image as the base image, but you can create a new document if you so desire. Make sure to unlock the layer and duplicate it so you can always go back if you make a huge mistake!
Step 4: Copy the tree image into your light bulb image. Don't worry if it is too big/doesn't fit. We will fix that.
Step 5: Change the opacity of the tree image so you can see the lightbulb through the tree image. The opacity slider can be found on the layer dialog box in the top right corner.
Step 6: Now, resize the tree image so it fits into the lightbulb. Use CMD+T (mac) or Ctrl+T (PC) to resize, and hold SHIFT in-order to keep the tree image's original dimensions and only change the scale. The size you want to make the tree inside the lightbulb is up to you, but make sure to leave part of the tree image outside the lightbulb. This will help later.
Step 7: Carefully erase the parts of the tree image that are outside the lightbulb. It helps to use a soft brush, I used a brush with 0% hardness.
Step 8: Turn opacity back up to 100% and make sure you haven't forgotten to erase any of the tree image.
Step 9: Change the layer style of the tree image from "Normal" to "Overlay". This should effectively blend the image, but you may want to turn the opacity down 10-15% in order to blend it a little better. The layer style dialog is next to the opacity slider on the left.
Step 10: Enjoy!
@cheerfulcallie I couldn't find a tutorial I liked online, so I made this one from scratch! I wouldn't do this for anyone, so lucky you :D